Added an Equalizer: 15-band (graphic) audio filter.
Added an Equalizer: 3-Band (Bass & Treble) audio filter. (Removed the old Bass & Treble audio filter.)
Added an Equalizer: Parametric audio filter.

More New Stuff

Added Segments parameter to the following video filters:
- Audio Level Visualization
- Audio Spectrum Visualization
- Audio Waveform Visualization
Added Settings > Job Priority to the main menu with a Normal option to improve performance on Intel 12th generation CPUs with E-cores. Low priority is the default as it has always been and is generally recommended.
Added Wayland compatibility to Flatpak for Linux.

Changes

Reduced audio distortion in Properties > Reverse for the best/MKV option.
Removed Use Higher Performance Waveforms (default is on but still in configuration).
Added a warning dialog when trying to use simple keyframes when advanced keyframes are being used.
Changed to remove full keyframes when switching to simple keyframes.
Added a warning dialog when trying to use advanced keyframes when simple keyframes are being used.
Changed to convert simple keyframes to advanced keyframes.
Changed tooltips on the Timeline and Keyframes toolbar to simplify and remove shortcuts from translated strings.
Improved compatibility of VA-API hardware encoding on Linux, particularly on Wayland.
Updated AV1, VP8, and VP9 encoders to latest releases.
Updated Rubberband (audio pitch library) to latest release.

Fixes

Fixed the appearance of Shotcut's description in Windows Task Manager (broke in v21.12).
Fixed filters when Export > From is Source or Each Playlist Item (broke in v21.05).
Fixed File > Export > Markers as Chapters if project contains transitions.
Fixed a possible crash moving clip inside blank on same track.
Fixed a crash when dropping a .mlt MLX XML file from a file manager to Playlist and then Timeline.
Fixed a crash on undo insert/overwrite after undo add transition.
Fixed Hold undo in Noise Gate audio filter.
Fixed audio mutes after setting an in or out point when playing not 1x forward in Source.
Fixed the Segment Gap goes to zero when reloading an Audio Spectrum Visualization filter.
Fixed Mask: Simple Shape > Rotate not working in presets.
Fixed page up/down incorrect when Current position (timecode) spin box has focus.
Fixed extra blanks being removed when drag moving a clip right with Ripple turned on.
Fixed paths to additional files used by some filters not saved as relative on Windows.
Fixed tiny clips created when trimming on the Timeline with Ripple All Tracks turned on.
Fixed removing simple keyframes.
Fixed the Text: Rich video filter shows the editor when playhead is not over selected clip.
Fixed Properties > Menu > Measure Video Quality (VMAF) not working on Windows.
Fixed a possible crash in Glitch video filter.
Fixed a crash changing Properties > Video > Rotation when the clip has a transition.
Fixed the Mask: From File video filter's Reverse option not working as intended.
Fixed broadcast standard non-integer frame rates (e.g. 30000/1001) for Matrosk and WebM files.
Fixed a bad job percentage complete when making a proxy or running a convert job on a GoPro video file.